Apple's decision to unleash Intel-based Mac systems six months ahead of schedule is proving less successful than the company anticipated. Two weeks following the Macworld Expo San Francisco keynote, sources report that sales of the Intel-based iMac are lower than Apple expected, even taking into account the seasonal post-holiday sales dip, suggesting the 2006 transition to Intel is going to be more difficult than the company has expressed. UPDATE: Good news for our Mac friends: new data now made available suggest that the iMac actually sells well.